Oxford Defense North Carolina, LLC will design, simulate, and demonstrate a metamaterial for use in a microwave integrating sphere. This device is similar to optical integrating spheres by causing incident radiation from a device under test to be uniformly distributed over the inside surface via multiple scattering. We will undertake the design, simulation, fabrication, and characterization of a metasurface that, when applied to the interior of a metal sphere, behaves as a near-ideal Lambertian scatterer. It is expected that the sphere be less than 20 wavelengths in diameter. We will also utilize computational electromagnetics to show the expected performance and bandwidth of the full integrating sphere.